1. Field of the Invention
The present invention relates to an IC memory card type radio modem to be connected to a PC card portion of a personal computer or the like and, more particularly, to an IC memory card type radio modem having a radio section adaptable to at least one type of radio infrastructure.
2. Description of the Prior Art
In conventional techniques, as disclosed in Japanese Unexamined Patent Publication No. 6-21880, communication is performed between a plurality of radio units and different types of radio systems. In the conventional techniques, however, switching between radio units and radio systems is performed in accordance with a judgement made by a user.
Furthermore, some conventional techniques use a plurality of radio sections to allow connection to a plurality of radio infrastructures, thereby allowing communication individually. However, this technique does not allow simultaneous communication upon connection to a plurality of channels.
In performing communication by using a conventional IC memory card type radio modem, a radio infrastructure must be selected in accordance with judgement made by the user of a portable information processing device. Assume that a radio infrastructure in a busy state moves outside a service area, which prevents communication from being sustained. In this case, the communication must be temporarily stopped, and the currently used radio infrastructure must be replaced with another radio infrastructure to resume the communication.
When data is to be sent to a plurality of addresses, the end of transmission of data to one address is confirmed first, and communication to another address is then performed after connection to the radio infrastructure is performed again. This operation must be repeatedly performed. Such re-transmission control leads to a considerable deterioration in information management efficiency.